Carrington Research Extension Center
North Dakota State University
NDSU Extension Service
North Dakota Agricultural Experiment Station

Ag Alert


WHEAT MIDGE EMERGENCE OCCURRING

Orange wheat blossom midge are being detected in the state. Midge have been found from Ellendale to Minot, and at economic levels in several counties as of July 2. Adult female midge emergence begins at about 1300 degree day (DD) units at a base temperature of 40 F. The following is a listing of dates when 1300 DD units accumulated, based on the ND Ag Weather Network, for selected south-central ND locations: Oakes = June 19, McLeod = June 20, Edgeley, Linton, and Dazey = June 25, Robinson = June 26, Jamestown = June 27, Streeter and Carrington= June 28, McHenry = June 29, and Harvey = June 30.

Scout wheat fields for the presence of wheat midge from head emergence until 80 percent of the heads have anthers visible (flowering). Field scouting must be in the evening from 9 p.m. until midnight. Wind speeds should be below 6 miles per hour and temperatures above 59 F. Visit three or four different sites in the field. At each location, count the number of midge on several sets of wheat heads (4 to 5 heads per set). Record and calculate your average for the field. If monitoring shows that the action threshold of an average of 1 adult midge per 4 to 5 heads has been reached, producers should consider the following guidelines for treatment with Lorsban 4E-SG: *If 30 percent of the wheat is heading, wait up to four days and then apply insecticide. *If 70 percent of the wheat is in the heading to flowering stage, optimum control should be achieved by treating. *If 30 to 60 percent of the heads are flowering, and at least one anther is visible, spray immediately, though control is likely to be reduced. *If 80 percent of the heads are flowering, treatments are not recommended.

Additional details on wheat midge scouting and management may be obtained from NDSU Extension Service offices.


Greg Endres, Area Extension Specialist/Cropping Systems, Email: gendres@ndsuext.nodak.edu
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